1500W LED, how close should I hover

I’m just starting with my first grow. I’m using a 3’ x 4’ grow tent, with a 4" fan and charcoal filter system and venting all the air outside. The temp is a steady 72 and humidity is about 30%. My grow light is a 1500w full spectrum LED and measures 11" x 18" When I put my light meter under it, at about 12" away it peg the meter at “full”. My question is, how close should my lights be? They are not hot so I could be very close if it would help. Is it possible to have too much light? Right now 1 week after sprouting, everything looks great and my light are about 12" away. Should I move the light closer as the plants start to get more leaves?

What is the flowering foot print of your LED, and at what height does the manufacturer recommend for that foot print? What kind of light do you have?

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I run 2 1800W cob led in similar space. 12-18 inches is where I keep them. Just don’t go so close that you lose the perimeter light coverage

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The LED is a Dimgogo 1500w triple chip full spectrum. (amazon) the coverage is 6.4’ x 6’ at 24" My lights are about 20" above the tops of the NL plants. the light meter reads 1800 lumens directly below the light at plant top and about 1500 lumens at the same height at the edge of my grow tent. 2000 lumens at 8" below the light.

I would start the light at the recommended height of 24", and then I would lower it an inch or so a every day or two until you get to 18". I would not run it closer than 18" personally.

I also will tell you that I started out with an almost identical light in a 4x4 tent. To properly flower cannabis plants, you will need to get another light just like it, or add enough of some other kinds of lights to get to the 500-600w range.

Thanks for the advice. I thought I was replying to you, but accidentally replied to someone else about this topic. Cheers…

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thanks bryan! from what I’ve heard back, it sounds like a second light will be helpful. Especially come flowering time.


One of them still works pretty well in veg… I had two of them going in my veg tent (mine are “1200w” - but true draw is 260w) for most of the veg on this one plant, but for the past month or so I just ran the one light:

You don’t NEED to get a second light if your plant(s) isn’t/aren’t going to fill the entire 4x4 up. You could grow to the foot print of the light - which, for flowering cannabis, is probably around 2x3.

Chances are, if it says it’s full spectrum, it’s not full spectrum.

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I have two of that same light. I’m currently running them at 24" but I just started a few weeks ago and it’s also my first grow.

@chief78 Give them some rest put them on a 18/6 light schedule every thing needs sleep she will thank you

Hey @Hogmaster mine are on 18/6 light schedule. I was saying I have mine at 24 inches from the top of the plant.

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